Field of the Invention
The present invention relates to a system of evaluating safety of wiring that connects a plurality of electronic apparatuses to one another through electrical wires and connectors.
Description of the Related Art
For example, in a wiring system that is configured of an input device, a control device, and an output device that are connected with one another through a wire harness (hereinafter, also simply referred to as harness), it is necessary to verify redundancy, whether electrical wires configuring the harness are connected with an appropriate route, after the system is constructed. For example, when a part of the harness in which a plurality of electrical wires are bundled is disconnected, in order to prevent an event of a device failure caused by disconnection of two electrical wires included in the bundle, it is necessary to bundle and wire the two electrical wires in different harnesses from each other (i.e., the two electrical wires are not included in the same bundle) and to fit out the plurality of harnesses with a route that physically separates the harnesses from one another. In a case of a system that has a large number of harnesses (the number of wirings) and a large number of terminal devices such as an input device or relay devices, however, it is not easy to check validity of a connection route from a plurality of wiring diagrams and to verify wiring safety.
Therefore, the present applicant has proposed, in Japanese Patent No. 5182973, a wiring connection confirmation system that makes it possible to easily confirm a connection route by a single electrical wire unit even in a large-scale system. Also, the present applicant has proposed, in Japanese Patent Laid-Open No. 2014-61841, a system that easily extracts harnesses having a one bundle risk and harnesses having a risk of safety impairing in simultaneous failure, and has further proposed, in Japanese Patent Laid-Open No. 2014-194676, a system that makes it possible to qualitatively analyze wiring safety of a complicated wiring structure.
Fault tree analysis (FTA) is widely known as a safety evaluation method. In a use requiring high safety, for example, in an aircraft, an electronic apparatus, a terminal device, and an electrical wire each have redundancy; however, the redundancy makes it difficult to verify safety.
In other words, in a large-scale system in which a plurality of sub-systems are integrated such as a control system for an aircraft, several tens or several hundreds of fault trees are analysis objects, and the plurality of fault trees configure a nest structure. In contrast, a plurality of terminal devices configuring the large-scale system and wirings that connects the terminal devices with one another are configured of thousands or tens of thousands of electrical wires. Therefore, although it is possible to determine whether the plurality of specific electrical wires belong to the same harness by the technology proposed by Japanese Patent Laid-Open No. 2014-61841, it is not easy to evaluate wiring safety through specification of electrical wires in redundant relationship and determination that the electrical wires are separately and independently from one another.
Accordingly, an object of the present invention is to provide a system that makes it possible to easily evaluate wiring safety.